1. Field of the Invention
The subject invention relates to a wheel and tire assembly for an automotive vehicle, and more particularly to an apparatus and method for mounting a valve stem into a wheel rim.
2. Description of the Prior Art
In the assembly of automotive wheel rims and tires, the tire is mounted onto the wheel rim and then inflated. Prior to mounting the tire, a valve stem is inserted into an aperture defined in the wheel rim to permit inflation of the tire. For manufacturing wheel rims on a large production scale, machines are used to automatically insert the valve stems into the wheel rims. Because the wheel rims of different sizes require differently sized valve stems, valve stemming machines must either operate on the wheel rims of a single size or be able to accommodate the use of several sizes of the valve stems.
Over the last few years, snap-in valve stems have become very popular in the automotive industry due to the ease of installation method. Clamp-in tire pressure monitoring systems type of a valve stem (the TPM) are similar to the snap-in valve stems, but also include a tire pressure monitor affixed to one end of the TPM. In order to install the TPM on the wheel rim, the TPM is placed through an opening defined in the wheel rim and then secured to the wheel rim by a retention nut over the TPM. A valve cap is then screwed onto the TPM to form an airtight seal and prevent dust and dirt from entering the valve.
Generally, as done in the past, mounting the valve stem into the wheel rim of any kind, have been performed manually. In particular, mounting the valve stem into the wheel rim has been performed by a stem-inserting tool. Such manual processes are expensive because of the labor and time involved. In addition, operations performed manually are subject to a processing error. Several prior art patents disclose processes for mounting the valve stem into the wheel rim. U.S. Pat. No. 6,026,552, for example, teaches a spinning device to spin a wheel, an optical sensor to locate a valve stem aperture while the wheel is spinning, and a press fitting device that can slide relative to the wheel and insert a valve stem after the valve stem aperture has been located.
U.S. Pat. No. 5,940,960, for example, teaches and automatic valve stemming apparatus including a spinning device to spin the wheel, an optical sensor to locate the valve stem aperture, and a valve stem insertion tool to insert a valve stem after the valve stem aperture has been located.
The art is also replete with various systems and methods, which involve a robot that installs a valve stem into a wheel rim. These systems are taught by U.S. Pat. Nos. 4,353,156; 5,940,960; 6,481,083; and 6,801,126. Other prior art devices utilize a rotatable carousel to dispense valve stems of varying sizes onto a valve stem insertion tool. The assembly line taught by the U.S. Pat. Nos. 4,353,156; 5,940,960; 6,801,126 and 6,481,083 are complex, bulky. Some of them require several separate valve stem mounting stations with the robotic manipulator moving the wheel rim to the respective valve stem mounting station. This prior art systems diminish assembly time and flexibility of assembling environment. These systems also performs numerous redundant operations, such as moving the wheel rim to different mounting stations which does not reduce time for assembly of the wheel rims and does not offer the flexibility needed in the modern manufacturing environment. Although the prior art valve stem installation systems are widely used in the automotive industry, these prior art designs have proven to be extremely complicated, and therefore non practicable, or have been inflexible in a manufacturing environment, particularly when a variety of valve stems are mated to a variety of the wheel rims.
One of the areas of continuous development and research is the pursuit of flexible systems operable to receive and process several differently configured rims. Another area is the pursuit of less costly valve stem insertion devices. Costliness can be defined by the capital investment required for putting the valve stem insertion system on the factory floor as well as the operating cost associated with the system. In pursuit of these goals, it would be desirable to develop a new design of the valve stem installation system adaptable for mating of at least two different valve stems into the wheel rim with high degree of accuracy and precision and at a high speed thereby eliminating the need of an extra unit, reduce space in manufacturing environment, and improving cost and efficiency of manufacturing process.